1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a home network system, and more particularly, to efficiently and stably providing state information on digital devices in a web-based home network system in real-time.
2. Description of the Related Art
Recently, as technologies for processing digital audio/video (A/V) are being rapidly developed, various digital devices such as digital televisions (TVs), set-top boxes, digital versatile disc (DVD) players, digital amplifiers or the like, have been installed and used in homes and offices. In addition, users in the homes or offices can conveniently control the various devices using a remote controller or the like. However, as the number of the digital devices installed in a limited space increases, devices are becoming more complicated, and controlling these devices has become more difficult.
Accordingly, technologies have been researched in which a plurality of digital devices are interconnected with one another to form one system, such that users can easily control the digital devices. According to these technologies, the digital devices can be connected to other digital devices through network interfaces to form one home network system.
As a result of the research, a technology standard, eXpandable Home Theater (XHT), has been developed and suggested to serve as middleware for digital home networking. The XHT technology as a digital TV based home network solution developed by Samsung Electronic Co., Ltd. has adopted as the standard of Consumer Electronics Association (CEA) in the United States of America.
According to the XHT technology, by using an IEEE 1394 cable capable of continuously transmitting a plurality of high definition (HD) signals, and the Internet Protocol (IP), not only can digital devices connected to a digital TV be controlled, but also a plurality of digital TVs can be controlled. By using the XHT technology, users can view digital broadcasting through a TV disposed in an inner room by using a digital broadcasting receiving function of the digital TV.
Since an inexpensive network interface unit (NIU) using the XHT technology is constructed in a type of a memory card, it can be easily changed according to different reception methods, such as territorial, satellite, and cable. Such versatility allows broadcasting providers to reduce costs. In particular, according to the XHT technology, various portal services can be provided through browsers installed in a digital TV.
In a home network system according to the XHT technology, a plurality of controlled devices, such as a DVD player, a digital hard disk drive, a set-top box, an amplifier, or the like, are controlled by a control device such as a digital TV, and each of them provides a user interface (UI). The control device displays the UIs provided by the controlled devices so as to allow a user to control the controlled devices.
Further, the control device periodically checks the state of the controlled device, and when the state of the controlled device is changed, the control device updates the user interface for the corresponding controlled device. In order to perform this function, the control device transmits a request signal requesting the state information of the controlled device to the controlled device. After the controlled device receives the request signal transmitted by the control device, when the state of the controlled device is changed, the controlled device transmits the state information of the controlled device to the control device. Even if the state of the controlled device is not changed, the controlled device transmits the same state information as the state information having been transmitted to the control device after a predetermined time passes, in order to maintain the connection state between the controlled device and the control device.
As a result, the control device receives the state information from the controlled device, and updates a web page of the corresponding controlled device or repeats a process of requesting the state information of the controlled device.
However, according to the related art, even though the state of the controlled device is not changed, the controlled device should transmit the same state information as the state information having transmitted to the control device in order to maintain the connection state between the control device and the controlled device, which results in increasing a load of the network.
In order to solve the above-described problems, various technologies (for example, refers to Korean Laid-Open Publication No. 2002-015856) have been suggested, but the above-described problems are not resolved.